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Conference netcad::hub_mgnt

Title:DEChub/HUBwatch/PROBEwatch CONFERENCE
Notice:Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7
Moderator:NETCAD::COLELLADT
Created:Wed Nov 13 1991
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:4455
Total number of notes:16761

4216.0. "Spanning tree on DECswitch 900EE" by HGOVC::SHUMCF () Tue Feb 18 1997 02:27

    Hello,
    
    Could anyone know what MIB variables affect the spanning tree
    performance on DECswitch 900EF. I know the typically failover time for 
    spanning tree is 45 seconds. Will it be possible to tune some parameters 
    to make it shorter ? Please help to give some hints.
    
    Thanks,
    cf
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4216.1Some hints.NETCAD::GALLAGHERTue Feb 18 1997 09:1250
The bridge MIB (rfc1493) has a spanning tree group.  Take a look at the 
objects dot1dStpForwardDelay and dot1dStpBridgeForwardDelay.  It appears
that you need to modify dot1dStpBridgeForwardDelay on your root switch
(indicated by dot1dStpDesignatedRoot).  Good luck.

						-Shawn


          dot1dStpForwardDelay OBJECT-TYPE
              SYNTAX  Timeout
              ACCESS  read-only
              STATUS  mandatory
              DESCRIPTION
                      "This time value, measured in units of hundredths
                      of a second, controls how fast a port changes its
                      spanning state when moving towards the Forwarding
                      state.  The value determines how long the port
                      stays in each of the Listening and Learning
                      states, which precede the Forwarding state.  This
                      value is also used, when a topology change has
                      been detected and is underway, to age all dynamic
                      entries in the Forwarding Database.  [Note that
                      this value is the one that this bridge is
                      currently using, in contrast to
                      dot1dStpBridgeForwardDelay which is the value that
                      this bridge and all others would start using
                      if/when this bridge were to become the root.]"
              REFERENCE
                      "IEEE 802.1D-1990: Section 4.5.3.6"
              ::= { dot1dStp 11 }

          dot1dStpBridgeForwardDelay OBJECT-TYPE
              SYNTAX  Timeout (400..3000)
              ACCESS  read-write
              STATUS  mandatory
              DESCRIPTION
                      "The value that all bridges use for ForwardDelay
                      when this bridge is acting as the root.  Note that
                      802.1D-1990 specifies that the range for this
                      parameter is related to the value of
                      dot1dStpBridgeMaxAge.  The granularity of this
                      timer is specified by 802.1D-1990 to be 1 second.
                      An agent may return a badValue error if a set is
                      attempted to a value which is not a whole number
                      of seconds."
              REFERENCE
                      "IEEE 802.1D-1990: Section 4.5.3.10"
              ::= { dot1dStp 14 }


4216.2p.s.NETCAD::GALLAGHERTue Feb 18 1997 09:183
p.s.  These parameters are on the ClearVISN MultiChassis
      Manager "Switch Configuration" screen reachable from
      the "Switch Summary" screen.